1. Field of the Invention
The present invention relates to an image processing apparatus and a method of processing images in which distance data are produced based on a pair of stereoscopic color images.
2. Discussion of Prior Art
A vehicle surrounding condition monitoring system using a stereoscopic camera is known. In this stereoscopic type vehicle surrounding condition monitoring system, small areas having identical brightness characteristic are identified from a pair of images taken by a pair of cameras and distance data are obtained from the amount of relative deviation between both small areas (stereo matching). In a prior stereoscopic type vehicle surrounding condition monitoring system, a monochrome image sensor (CCD or CMOS sensor) are introduced and vehicle surrounding conditions are recognized based on brightness information in monochrome images.
In case of employing color images in place of monochrome ones, since color information is added to the stereoscopic image processing in addition to brightness information, an enhancement of reliability can be expected in the distance data obtained. Additionally, more complicated recognition of circumstances as well as more accurate recognition of traveling conditions are available. However, actually, systematic studies about how a plurality of images of primary colors constituting a color image should be processed and what information should be extracted from the primary color images, have never been made sufficiently.
Further, recently, with an advance of image processing related technologies, adoptions of color images spread in the field of image processing and as a result manufacturing cost of color image sensors is becoming inexpensive year by year. Hence, it is desirable to adopt a color image sensor into the stereoscopic type vehicle surrounding condition monitoring system.